Standard vs Itemized Deduction Calculator Formula
Understand the math behind the standard vs itemized deduction calculator. Each variable explained with a worked example.
Formulas Used
Standard Deduction
standard_amount = filing_statusItemized Deductions
itemized_amount = itemized_totalAdditional Tax Savings
better_option = abs(itemized_total - filing_status)Variables
| Variable | Description | Default |
|---|---|---|
filing_status | Standard Deduction (by filing status)(USD) | 14600 |
mortgage_interest | Mortgage Interest(USD) | 8000 |
state_local_tax | State & Local Taxes (SALT)(USD) | 7000 |
charitable | Charitable Donations(USD) | 3000 |
medical | Medical Expenses (over 7.5% AGI)(USD) | 0 |
itemized_total | Derived value= mortgage_interest + min(state_local_tax, 10000) + charitable + medical | calculated |
How It Works
Standard vs Itemized Deductions
Choose whichever is higher to reduce your taxable income.
2024 Standard Deduction
Common Itemized Deductions
Worked Example
Single filer: $8,000 mortgage, $7,000 SALT, $3,000 charity.
filing_status = 14600mortgage_interest = 8000state_local_tax = 7000charitable = 3000medical = 0
- 01Itemized = $8,000 + $7,000 + $3,000 = $18,000
- 02Standard = $14,600
- 03Itemizing saves $18,000 - $14,600 = $3,400 more
Frequently Asked Questions
Should I itemize or take the standard deduction?
Take whichever is larger. Since the 2017 tax reform nearly doubled the standard deduction, about 90% of taxpayers now take the standard deduction.
What is the SALT cap?
State and Local Tax deductions are capped at $10,000 ($5,000 if married filing separately). This significantly impacts taxpayers in high-tax states.
Can I switch between standard and itemized each year?
Yes. You can choose whichever is more advantageous each tax year. There is no requirement to be consistent.
Ready to run the numbers?
Open Standard vs Itemized Deduction Calculator